1. Field of the Invention
The present disclosure relates to a controller for confirming the contact status of a latch relay in an electric power meter.
2. Description of the Related Art
Latch relay embedded in a digital electric power meter or smart meter as a switch device capable of switching at least one of lines for supplying electric power to the side of an electric load from the side of an electric power source maintains the open or closed status once the opening or closing of a contact has been made.
For an example of such a digital electric power meter and a latch relay according to the related art, the following patent literature disclosed by the applicant of the present disclosure is described below for reference.
(Patent Document 1) KR10-1017761 B1
However, a digital electric power meter embedded with a latch relay according to the related art uses a method of determining the contact switching status according to stored history data on the contact switching status of a latch relay, namely, previous contact switching status information stored in the memory other than a method of directly sensing the contact switching status information of a latch relay to recognize the contact switching status thereof.
Accordingly, when a digital electric power meter is moved for a new installation or separated from the existing installation location and then reinstalled for repair, the stored previous contact switching status information of a latch relay may be different from the real contact switching status of the latch relay due to a mechanical shock or vibration, thus causing a problem of inducing an electrical safety accident.